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coresight-etm4x: Controls pertaining to the selection of resources

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Adding sysfs entries to control the selection of the resources the
trace unit will use as triggers to perform a trace run.

Signed-off-by: Pratik Patel <pratikp@codeaurora.org>
Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Pratik Patel 2015-05-13 10:34:17 -06:00 committed by Greg Kroah-Hartman
parent add2d5d0d1
commit 6afa8a1387
2 changed files with 87 additions and 0 deletions
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12
Documentation/ABI/testing/sysfs-bus-coresight-devices-etm4x
View file

@ -230,3 +230,15 @@ Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Controls the operation of the selected counter.
What: /sys/bus/coresight/devices/<memory_map>.etm/res_idx
Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Select which resource selection unit to work with.
What: /sys/bus/coresight/devices/<memory_map>.etm/res_ctrl
Date: April 2015
KernelVersion: 4.01
Contact: Mathieu Poirier <mathieu.poirier@linaro.org>
Description: (RW) Controls the selection of the resources in the trace unit.

75
drivers/hwtracing/coresight/coresight-etm4x.c
View file

@ -1707,6 +1707,79 @@ static ssize_t cntr_ctrl_store(struct device *dev,
}
static DEVICE_ATTR_RW(cntr_ctrl);
static ssize_t res_idx_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
unsigned long val;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
val = drvdata->res_idx;
return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
}
static ssize_t res_idx_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
unsigned long val;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
if (kstrtoul(buf, 16, &val))
return -EINVAL;
/* Resource selector pair 0 is always implemented and reserved */
if ((val == 0) || (val >= drvdata->nr_resource))
return -EINVAL;
/*
* Use spinlock to ensure index doesn't change while it gets
* dereferenced multiple times within a spinlock block elsewhere.
*/
spin_lock(&drvdata->spinlock);
drvdata->res_idx = val;
spin_unlock(&drvdata->spinlock);
return size;
}
static DEVICE_ATTR_RW(res_idx);
static ssize_t res_ctrl_show(struct device *dev,
struct device_attribute *attr,
char *buf)
{
u8 idx;
unsigned long val;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
spin_lock(&drvdata->spinlock);
idx = drvdata->res_idx;
val = drvdata->res_ctrl[idx];
spin_unlock(&drvdata->spinlock);
return scnprintf(buf, PAGE_SIZE, "%#lx\n", val);
}
static ssize_t res_ctrl_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t size)
{
u8 idx;
unsigned long val;
struct etmv4_drvdata *drvdata = dev_get_drvdata(dev->parent);
if (kstrtoul(buf, 16, &val))
return -EINVAL;
spin_lock(&drvdata->spinlock);
idx = drvdata->res_idx;
/* For odd idx pair inversal bit is RES0 */
if (idx % 2 != 0)
/* PAIRINV, bit[21] */
val &= ~BIT(21);
drvdata->res_ctrl[idx] = val;
spin_unlock(&drvdata->spinlock);
return size;
}
static DEVICE_ATTR_RW(res_ctrl);
static ssize_t cpu_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
@ -1757,6 +1830,8 @@ static struct attribute *coresight_etmv4_attrs[] = {
&dev_attr_cntrldvr.attr,
&dev_attr_cntr_val.attr,
&dev_attr_cntr_ctrl.attr,
&dev_attr_res_idx.attr,
&dev_attr_res_ctrl.attr,
&dev_attr_cpu.attr,
NULL,
};